Le travail présenté dans cette thèse consiste à l’étude des rejets en mer, par émissaire marin, des eaux usées urbaines des collectivités littorales. Nous focalisons notre étude sur les rejets chargés de matières en suspension. Ces matières risquent de déposer autour du point de rejet et créent une zone très polluée. Dans ce contexte, nous procédons à la modélisation de la déposition des particules transportées en suspension par les rejets urbains dans la zone proche du point de rejet dite « champ proche ». Ceci est fait dans le but de mieux comprendre ce phénomène et de pouvoir déterminer, en conséquence, le niveau de traitement à l’amont ainsi que la configuration du dispositif de rejet en fonction des capacités du milieu récepteur à assimiler la pollution solide. Nous avons réalisé ce travail en trois parties. Dans la première partie, nous avons étudié les rejets urbains dans les zones littorales, les caractéristiques des eaux usées urbaines et celles des particules solides transportées par ces eaux. Nous avons aussi étudié la relation entre les différents critères de qualité des eaux du milieu récepteur et le rejet urbain ainsi que le rôle de l’émissaire marin dans la réduction de l’impact environnemental du rejet sur le milieu marin. Dans la deuxième partie, nous nous concentrons sur la zone proche de l’émissaire marin. Il s’agit du jet turbulent issu du rejet. Dans ce contexte, nous étudions le comportement hydrodynamique du jet et nous le modélisons. Ceci est fait par l’établissement d’un modèle Lagrangian pour l’étude du champ proche (modèle de la phase liquide). Dans la troisième partie, nous construisons un modèle pour anticiper la déposition des particules solides transportées par les rejets urbains (modèle de la phase solide). Ce modèle se base sur le phénomène de concentration préférentielle. Il est couplé avec le modèle Lagrangian du comportement hydrodynamique du jet, conçu dans la deuxième partie. Le modèle est validé par des données expérimentales représentant le taux de déposition longitudinale des jets horizontaux et inclinés flottants dans un milieu stationnaire, en présence de co-courant et les jets horizontaux non flottants dans un milieu stationnaire. Nous terminons ce travail par une analyse de sensibilité pour étudier les effets d’un certain nombre de paramètres du jet et du milieu ambiant sur le comportement hydrodynamique du jet et sur le taux de déposition. / In this study, we are interested in the problem of marine wastewater discharge via the submarine outfall. We emphasize on the urban discharge laden with suspended solids. These suspended solids may depose around the discharge point in the sea and create a highly polluted zone. The objective of this study is the modeling of deposition of suspended solids from urbandischarge in the zone near the discharge point, called nearfield, in order to understand the phenomenon and determine thereafter the treatment level upstream in addition to the configuration of the discharge point depending on the capacity of receiving milieu to assimilate the solid pollution. The work is realized in three parts. In the first part, we studied the management of urban discharge in coastal areas, including the characteristics of urban wastewater, and those of solid particles transported by wastewater. We studied also the relation between the receiving water quality criteria and urban discharge in addition to the role played by the submarine outfall in the reduction of environmental impact of the urban discharge on the marine milieu. In the second part, we concentrate on the zone near the submarine outfall that means the turbulent jet issued from the discharge. We study the hydrodynamic behaviour of the jet, the modeling of this behaviour. Then we present our Lagrangian model designed for the study of nearfield (liquid phase model). In the third part, we construct a model to anticipate the deposition of solid particles driven to the sea by the urban discharge (solid phase model). This model is based on the phenomenon of preferential concentration and is coupled with the Lagrangian model of hydrodynamic behaviour of the jet designed in the second part. The model is validated by experimental data presenting the longitudinal deposition rate of horizontal and inclined jets in stationary ambient, in presence of coflow in addition to the case of horizontal non-buoyant jets in stationary ambient. Finally, a sensitivity analysis is performed where we studied the effects of many parameters of the jet ad the ambient milieu, on the hydrodynamic behaviour of the jet and on the deposition rate.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of the research was to determine the strawberry fruit yield and quality in three different closed soilless systems with two substrates. The experiment was conducted in a screenhouse in the Department of Fitotecnia at the Universidade Federal de Santa Maria, from April to November, 2006. The experimental set up was a 3 x 2 factorial design with four replications. Treatments were the three soilless systems and the two substrates. The soilless systems consist of plastic bags, plastic troughs and growing beds, all of them elevated from the soil. The substrates were an inert substrate (sand) and an organic substrate (Plantmax PXT®). Drip fertigation was used in the plastic bags, while subirrigation was done in the other two systems. A standard complete nutrient solution was utilized and there was not any disposal of it during the experiment. A significant interaction among substrates and systems was observed. In the case of the sand, best results were obtained with plastic troughs reaching a mean fruit yield of 122.09 t ha-1, which was 8.13% e 8.33% higher than the plastic bags and the growing beds, respectively. In the case of the organic substrate, the mean fruit yield in the system of growing beds (143.58 t ha-1) was 10.9% and 29.33% superior to the plastic bags and plastic troughs, respectively. Neither the soilless systems nor the substrates influenced the fruit quality characteristics of firmness, soluble solids and titratable acidity. / O objetivo do trabalho foi determinar a produtividade e qualidade do morangueiro em sistemas fechados de cultivo sem solo com substratos. O experimento foi conduzido dentro de um abrigo telado no Departamento de Fitotecnia da Universidade Federal de Santa Maria, entre abril e novembro de 2006. Os tratamentos foram constituídos por três sistemas de cultivo e dois substratos, em esquema fatorial 3x2, no delineamento inteiramente casualizado, com quatro repetições. Os sistemas de cultivo foram sacolas fertirrigadas por tubos gotejadores, calhas e leito de cultivo. Os substratos foram a areia como substrato inerte e o Plantmax PXT® como substrato orgânico, fertirrigados com solução nutritiva completa, sem descartes durante o período do experimento. Houve interação significativa entre os substratos e os sistemas. Na areia, destacou-se o cultivo nas calhas, com uma produtividade média de 122,09 t ha-1, sendo 8,13% e 8,33% superior às sacolas e ao leito de cultivo, respectivamente. No substrato orgânico, a média mais elevada foi equivalente a 143,58 t ha-1, obtida no leito de cultivo, superior às sacolas em 10,9% e às calhas em 29,33%. Não houve influência dos substratos nem dos sistemas sobre a qualidade da fruta, caracterizada através da firmeza, °Brix e acidez titulável.

L’adsorption des gaz dans les solides micro/mésoporeux et la solubilisation des gazdans les liquides sont des phénomènes physiques très bien connus. En revanche, lasolubilisation des gaz dans un liquide confiné à l’intérieur d’un solide (système hybride) estun domaine très peu étudié, malgré des applications importantes, notamment dans l’extractiondu pétrole, les ciments ou encore les réacteurs catalytiques triphasiques. Nous avons montréexpérimentalement que la solubilité du CO2 et H2 augmente quand la taille de pores du solideest de l’ordre du nanomètre. Un des objectifs de cette thèse était d’optimiser le couple solidesolvant(système hybride) et les conditions de température et de pression pour augmenter lestockage de H2 pour les applications de stockages. Dans le système Aérogel/éthanol à 50 barset 0°C, la solubilité de H2 est 8,5 fois supérieure à la solubilité mesurée dans le liquide seul,représentant une masse de 6,2g d’hydrogène stocké par kg de solide. Le second objectif étaitde comprendre les paramètres clefs de ce phénomène apparent de « sursolubilité » dans lessystèmes hybrides. En comparant différents solides poreux (zeolithes, MOF, MCM, silice),nous avons montré le rôle majeur des propriétés d’interfaces. Les phénomènes desolubilisation ont été modélisés à l’échelle moléculaire par GCMC et validéesexpérimentalement. Il apparait que le mécanisme de sursolubilisation provient d’unestructuration en couche des molécules de solvants en interactions avec les parois dumésopore. / The adsorption of gases in micro/mesoporous materials and solubility of gases inliquids are physical phenomena well known. On the other hand, solubility of gases in liquidsconfined inside a solid (hybrid system) has not been entensively studied, despite the importantapplications such systems can have in the areas of oil extraction, cement and triphasiccatalytic reactors. We have shown experimentally that the solubility of CO2 and H2 increaseswhen the size of the pores of the solid is in the nanometer range. One of the objectives of thisthesis was to optimize the couple a solid and a solvent into a hybrid system and the conditionsin which to increase the H2 storage capacity. In an aerogel/ethanol hydrid system at 50 barand 0 ° C, the solubility of H2 is 8.5 times greater than the solubility measured in the singleliquid, representing a mass of 6.2 g of hydrogen stored per kg of solid. The second objectivewas to understand this apparent phenomenon of oversolubility and the key parameters in thehybrid systems. By comparing different porous solids (zeolites, MOFs, MCM-41 and silica),we have shown the major role of the properties of interfaces. The phenomena of solubilsationwas modelled by GCMC and experimentally validated. It appears that the mechanism ofoversolubilisation comes from structuring the solvent molecules in interactions with the wallsof the mesopore layered.

L’objectif de ce mémoire est de présenter une étude aussi complète que possible de l’effet Stark dans les toupies asymétriques de type X2Y4 possédant le groupe de symétrie D2h et de l’appliquer au problème de la spectroscopie de l’éthylène piégé dans une zéolithe. Pour la première fois, un formalisme tensoriel adapté à l’étude de l’effet Stark pour la chaine de groupes O(3) D2h a été développé. Parallèlement au développement du modèle théorique, des programmes informatiques ont été mis au point sous la forme d’une nouvelle génération de logiciel appelé D2hTDS-ST utilisant une base plus simple, permettant une économie en temps de calcul. Sur la base des outils théoriques et informatiques ainsi qu’à partir des spectres expérimentaux enregistrés au laboratoire, nous avons fait une première estimation de la valeur du champ électrique effectif moyen produit par la silicalite-1. Les valeurs du champ électrique obtenues avec notre méthode sont cohérentes avec les valeurs obtenues par les calculs ab initio PBE1PBE6-31++G(2d,2p). / The objective of this report is to present a study as complete as possible of the Stark effect in the asymmetric top molecules of X2Y4 type possessing the D2h symmetry group and to apply it to the problem of the spectroscopy of the ethylene molecule trapped in a zeolite. For the first time, a tensorial formalism adapted to the study of the Stark effect for the O(3) D2h group chain was developed. In parallel, a computer package was worked out as a new generation of software called D2hTDS-ST using a simpler basis, allowing an economy in the calculation time. On the basis of the theoretical and computing tools as well as from the experimental spectra, recorded in the laboratory, we made a first estimation of the average effective electric field produced by silicalite-1. The values of the electric field obtained with our method are coherent with the values obtained by the ab initio PBE1PBE6-31++G(2d,2p) calculations.

In this thesis there can be found various examples from Monge projection. The theory is summarized in the beginning, which is important of understanding the projection and for solving the examples. There are also examples of solving axial affinity and central collineation. Then there is a chapter about the projection of all types of angular and rotational solids, which are solved at the secondary schools. Then follows a chapter, where the sections of these solids are constructed. In the last chapter, there are solved intersection of solids from each type. Powered by TCPDF (www.tcpdf.org)

Dans cette thèse, la biodégradation et le devenir des matières organiques lentement biodégradables contenues dans les eaux usées ont été étudiés. La thèse s’est particulièrement penchée sur l’étude du processus d’hydrolyse dans la mesure où plusieurs auteurs considèrent qu’il s’agit du processus limitant durant la dégradation des matières considérées. L’analyse des résultats de la littérature en complétés de ceux que nous avons obtenu en laboratoire a permis d’identifier et ainsi souligner les manques par rapport aux mécanismes qui régissent la dégradation des matières organiques lentement biodégradables. Ensuite, nous avons confronté ces résultats expérimentaux (expériences réalisées en batch sur des substrats type « particules décantables ») aux modèles conventionnels du traitement des eaux mais aussi à d’autres modèles moins usuels afin d’évaluer les performances de ces derniers à décrire l’hydrolyse des différents substrats. La difficulté de ces modèles à décrire la diversité des situations rencontrées nous a amené à développer un nouveau modèle qui tient compte des propriétés physiques et géométriques du substrat et qui permettrait d’améliorer la caractérisation du processus d’hydrolyse. Enfin, nous nous sommes intéressés à la distinction d’une biomasse hydrolytique dans la masse cellulaire totale et de déterminer son origine. Il a été clairement démontré que l’hydrolyse des PSS dans les procédés à boues activées était plus impactée par les bactéries indigènes, initialement adsorbées dans le réseau, que par les bactéries exogènes, en provenance d’un inoculum de boue activées. / In this work, the fate and biodegradation of slowly biodegradable organic matter contained in wastewaters were investigated. The hydrolysis process was particularly targeted as many sources proved that it controls the fate of the considered substrate. First, a synopsis of the literature results related to this topic as well as internal results were investigated especially in terms of respirometric aspects (OUR measurement) in order to identify differences and/or similarities between the experiments and, thus, address gaps in knowledge of the mechanisms that are involved in the hydrolysis of this matter. Then, in the second part of this thesis, experimental data from batch respirometric tests (performed in our laboratory), involving typical slowly biodegradable matter that are found in wastewaters (e.g. Particulate settleable solids, toilet paper…), were confronted to conventional (IAWQ models) and non-conventional models to evaluate the efficiencies of those models to describe the hydrolysis step. In the third part of this thesis, based on hypotheses, a novel conceptual framework was developed in order to enhance the description of the hydrolysis process. The physical properties (density, size, shape) of the components (bacteria and substrate) were taken into account in this model. Finally, in the fourth and last chapter of this thesis, the specific role of each bacterial population involved in the biodegradation of slowly biodegradable organic matter was assessed. It was here clearly evidenced that the hydrolysis of PSS in activated sludge processes appears more influenced by the initially adsorbed bacteria onto the sewage than by the added AS-inoculum concentration.

Modern solid state chemistry is inconceivable without theoretical treatment of solids thanks to the availability of efficient and accurate computational methods. Being developed mainly by physicist's community and deeply rooted in the formalism of reciprocal space, they often lack connections to familiar chemical concepts, indispensable for the chemical understanding of matter. Quantum chemical topology approach is a powerful theory able to efficiently recover chemical entities from the abstract description of a system given by its density matrices. It can be used to partition any many-electron system into the atoms, using the topology of electron density or for instance into atomic shells, using the topology of ELI-D field. Various characteristics of interactions between these chemical building blocks can be obtained applying bonding indicators, e.g. from the analysis of domain-averaged properties. Quantum chemical topology methods have been extended in the current work for the applications on the diversity of theoretical methods widely used for the description of solids nowadays – from the mean field Kohn-Sham density functional theory to the reduced one-electron density matrices functional theory or from the scalar-relativistic methods to the many-component formalisms employing spinor wavefunctions. It has been shown, that they provide chemically meaningful description of the bonding which is universally applicable to any class of extended systems, be it ionic insulator, covalent solid or metal. It has been shown, that the relativistic effects on the chemical bonding can be easily revealed using extensions of bonding indicators developed in the current work. Classical chemical concepts like Zintl-Klemm concept can be easily recovered with these descriptions. Intimate connection between the class of the material and the degree of chemical bonding delocalization has been also established. All these methods have been successfully applied to the various classes of solids and delivered novel insights on their crystal structure, properties, solid state transitions and reactivity.

No description available.

L'endommagement des matériaux ductiles est un processus impliquant trois étapes : la nucléation, la croissance et la coalescence de vides. La phase de croissance des vides a été largement étudiée dans la littérature. Il a été montré que, durant cette étape, la forme des vides joue un rôle fondamental sur le comportement macroscopique du matériau. Dans le cas de sollicitations dynamiques, les effets micro inertiels, qui résultent des accélérations subies par la matrice au voisinage du vide, influent eux aussi fortement sur la croissance des vides. Cependant, les travaux intégrant simultanément ces deux contributions (effets inertiels et forme) sont très rares. L'objectif de ce travail est de proposer un modèle de comportement pour les matériaux poreux qui prend en compte la forme des vides et les effets micro inertiels. Dans une première partie, un volume élémentaire représentatif défini par deux ellipsoïdes allongés confocaux est utilisé pour représenter le matériau poreux. La matrice est rigide viscoplastique. En se basant sur les travaux de Molinari et Mercier (2001), la contrainte macroscopique se décompose en une partie statique et une partie dynamique. La contrainte statique est décrite par le modèle de Gologanu et al. (1997). La contrainte dynamique est obtenue en adoptant le champ de vitesse de Gologanu et al. (1993). Avec cette modélisation, il est montré que la contrainte dynamique est liée de façon quadratique au tenseur des vitesses des déformations et de façon linéaire à sa dérivée par rapport au temps. Le modèle fait l'objet d'une validation sur la base de comparaisons avec des résultats de calculs par éléments finis. Différentes forme de vides et valeurs de la porosité ont été considérées. Dans une seconde partie, le cas de matériaux contenant des vides aplatis est abordé ; le volume élémentaire représentatif est défini par deux ellipsoïdes confocaux aplatis. La contrainte statique est toujours décrite par le modèle de Gologanu et al. (1997). La contrainte dynamique est obtenue en adoptant le champ de vitesse de Gologanu et al. (1994). La procédure de validation est identique à celle mise en œuvre dans le cas des vides allongés. Une bonne adéquation entre les résultats du modèle et les résultats de calculs par éléments finis est retrouvée. L'utilisation des surfaces d'écoulement permet de mettre en lumière les effets de la forme des vides sur le comportement du matériau poreux sous chargement dynamique. En fonction du chargement appliqué, certaines géométries de vide favorisent la déformation du matériau. Le cas particulier du vide sphérique est étudié comme limite des deux modèles. La continuité des deux modèles est démontrée. L'évolution de la porosité et de la forme des vides dans un matériau poreux sous chargement dynamique est analysée. Des comparaisons avec des résultats de simulations par éléments finis sont proposées. L'influence de la triaxialité et de la vitesse du chargement sur le comportement dynamique du matériau poreux est étudiée, ainsi que celle de la forme initiale du vide. Au final, il est démontré que le modèle développé dans cette thèse permet de retrouver les tendances fournies par les calculs éléments finis / The ductile fracture mechanism involves three stages: void nucleation, void growth and void coalescence. Under dynamic loading conditions, void growth is strongly affected by microinertia effects resulting from the local acceleration of the matrix material in the vicinity of the void. Several works devoted to quasi-static conditions also show that void shape has a strong impact on the behavior of porous ductile materials. However, there exist only few works considering the combined effect of these two contributions. In the present work, we propose an original, multi-scale constitutive model of porous materials, taking into account void shape and micro-inertia effects. In a first step, a representative volume element defined by two confocal prolate spheroids is used to represent the porous material. The matrix behavior is assumed to be rigid-viscoplastic. Based on the work of Molinari and Mercier (2001), the macroscopic stress is the sum of a static and a dynamic part. The static contribution is described by the Gologanu et al. model (1997). The dynamic stress is derived by choosing the trial velocity field proposed by Gologanu et al. (1993). With the present modeling, a link is established between the macroscopic dynamic stress, on the one hand and, the macroscopic strain rate tensor and its time derivative on the other hand. To validate the proposed model, finite element computations have been performed for different void geometries and void volume fractions. The influence of micro-inertia on the macroscopic flow surface is analyzed and a good agreement between modeling and simulations is observed. In a second step, a representative volume element defined by two confocal oblate spheroids is used to represent the porous material. For this configuration, the static contribution is also described by using the Gologanu et al. model (1997), while the derivation of the dynamic stress is based on the trial velocity field proposed by Gologanu et al. (1994). As for the prolate case, a good agreement is retrieved between model predictions and results of finite element computations. The spherical void configuration is investigated as the limit case for the oblate and prolate models. The continuity between the two models is established. Finally, the proposed models are combined to investigate the porosity and void shape evolutions in a porous solid under dynamic loadings. A parametric study has been performed by varying the stress triaxiality, the initial void shape and the loading rate. Significant void shape variations are observed for low triaxiality loadings. With the present modeling, the void can evolve from prolate to oblate shapes (and the reverse). Model predictions are compared to finite element computations

[pt] Catalisadores Mo-SnO2 foram obtidos a partir da precipitação, em solução aquosa, do SnO2.xH2O na presença de (NH4)2Mo7O24 em dois teores de Mo: 5,5 e 14,5 por cento em massa, os quais foram, posteriormente, impregnados com 1 por cento em massa de cátion sódio. Os sólidos obtidos foram caracterizados por espectroscopia de reflectância difusa na região do UV- visível, difração de raios-X, adsorção de nitrogênio, redução à temperatura programada, e espectroscopia de absorção na região do infravermelho de metanol e de piridina adsorvidos. Verificou-se que a presença de sódio resulta na diminuição da área específica, na eliminação dos microporos e dos poros de diâmetro elevado, sendo os últimos referentes aos polimolibdatos. Verificou-se, também, que a presença de sódio propicia o consumo das espécies dispersas de molibdênio, resultando na sua aglomeração, com formação de polimolibdatos. Com relação à acidez dos sólidos, verificou-se que a ação do Na é função da concentração superficial de Mo. No caso de baixa concentração de Mo, observou-se que o sódio promove a eliminação dos sítios de Brönsted e a formação de sítios fracos de Lewis; já para a concentração elevada, observouse, além da formação de sítios fracos de Lewis, um aumento da concentração dos sítios de Brönsted. Assim, o Na altera de forma significativa a textura, a acidez e as espécies de Mo presentes nos catalisadores Mo- SnO2. / [en] Mo-SnO2 catalysts were prepared by SnO2.xH2O precipitation with ammonium heptamolybdate solution. Two Mo amounts were used: 5,5 and 14,5 percent (wt); Afterwards, these samples were impregnated with 1 percent Na (wt). These solids were characterized by nitrogen adsorption, UV-visible diffuse reflectance spectroscopy, temperature programmed reduction, X-ray diffraction, infrared spectroscopy of adsorbed pyridine and methanol. It was observed that the Na addition decreases the surface area of the Mo-SnO2 solids, caused by elimination of the micropores and the large pores of polymolybdates. It was also verified that Na promotes the agglomeration of Mo species, i.e. the amount of Mo dispersed species decreases and the polymolybdate one increases. Sodium also changes the solid acid properties: for the low Mo amount it was observed that Na promoted the formation of weak Lewis acid sites and the elimination of Brönsted sites; on the other hand for the high Mo amount, both Brönsted and weak Lewis acid sites content increased when Na was added. These results showed that sodium changed the texture, the Mo species and the acid properties of Mo-SnO2 catalysts.